Cylinder head cooling means



Sept. 10, 1940. K, BRQWNE 2,214,321

CYLINDER HEAD COOLING MEANS Filed June 18, 1938 AT'TOR Patented Sept. 10, 1940 PATENT OFFICE 2,214,321 CYLINDER. HEAD COLING.MEANS Kenneth A. Browne, Westwood, N. .L, assignor to Wright Aeronautical Corporation, a corporation of New York Application June 18, 1938, Serial No. 214,443

7 Claims.

This invention relates to a novel air cooling fin disposition, the drawing illustrating the device applied to a. re-entrant head for a sleeve valve internal combustion engine cylinder.

A prime object of the invention is to provide a finning system which will give adequate air fiow and conductivity for cooling a surface located at the bottom of a depression as in a re-entrant cylinder head. An associated object is to provide adequate entrance and exit area for air fiow without unduly sacrificing the fin area.

Other objects and advantages of the invention will be obvious fromfor will be pointed out in the following description with reference to the drawing in which:

Fig. 1 is a perspective section through a head embodying the invention;

.Fig. 2 is a plan view of the head, and Fig. 3 is a section on the lines 3-3 of Fig. 2. In the drawing the cylinder head unit comprises a base l0 disposed at the bottom of an integral annular wall l2 having a flange M at its upper end by which the head unit is secured to a cylinder barrel l6 by clamp screws I8. The wall I2 is spaced from the barrel IE to accommodate a valve sleeve 20 and the head is provided with a suitable junk ring 22.

The base It) is provided with bushings 24 tapped to receive spark plugs. The fins consist of a plurality of concentric segmental elements 26, preferably flanged at their lower end, as in dicated at 28, said flanges forming spacers and affording adequate contact area whereby the fins may be placed in intimate thermal contact with the head l0, as by brazing. An inner fin element 30 is a complete tube but, around the spark plug bushings, the other fins are cut away to form entrance and exit ports, as will be clear from the perspective view of Fig. 1. The cutaway portions of the fins comprise V notches conformed at the top of the fins, to the dotted line 32 of Fig. 2 and, at the bottom, to the line 33, the proportions being such that the air flow area through each notch is equal to the air flow area through the two arcuate portions of the fins which are left intact. The cutaway segments of the fins aggregate to provide opposed clear cavities or zones within each of which a spark plug may be located. The zones do not extend to the base of the cylinder head so that short fin portions cover the base. As is obvious from Fig. 3, cooling air is directed toward the fins by the scoop 34, but in virtue of the open zone, air may enter the latter and then enter the interfin spaces in a circumferential direction without undergoing severe changes in direction as would be necessary if the open cavities were non-existent. In the latter case, air would have to flow axially into the tops of the fins and then change direction within the fin spaces to follow 5 circumferentially around them. The open zones allow for a large volume of airflow over the head without extreme turbulence which latter would result if the cooling air were required to enter vertically downward between full height fins. 10.

The top of the head is provided with a suitable scoop or baffle indicated by the dotted line 34 of Figs. 2 and 3. The fiow path accordingly, is inthrough the forwardly facing scoop 34; downwards where the fins are cut out around the spark plugs, whereupon the-fiow bifurcates and fiows circumferentially around the fins, meeting at the rear cut-out where it flows upwardly around the rear spark plug and out of the rear scoop. It is a feature of the proportions shown 0 that the air flow areas throughout this path are substantially equal. It should be noted that the air scoop or deflector does not necessarily enter the head and preferably lies completely above it. The fins 26 may extend considerably above the 35 top of the head to increase the cooling surface.

While the invention has been shown as for a steel head and brazed-in fins, preferably of copper, it will be obvious that the fins may be cast or machined integral with the head unit or the head may be cast upon the fin assembly.

While I have described my invention in detail in its present preferred embodiment, it Will be obvious to those skilled in the art, after understanding my invention, that various changes and modificatio-ns may be made therein without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications and changes.

I claim as my invention: 40

1. In combination with a cylinder head having a central depression, substantially concentric annular fins within said depression said fins being interrupted at front and rear zones, and air scoops communicating with said zones to lead 45 air into one zone for fiow circumferentially around the fins and out of the other zone.

2. A cylinder head comprising a well shaped member having a base to be cooled. substantially annular fins in thermal contact with said base and extending towards the top of said head, said fins having segments cut therefrom to provide areas of entrance and exit air flow and entrance and exit air scoops communicating with respective areas. 55

3. In combination with a cylinder head having a depression, concentric annular fins within said depression, the outer fins being cut-away to com prise front and rear segmental air entrance and exit areas and air scoop means communicating with said areas to induce air flow circumferentially of the fins.

4. In combination with a cylinder head having a depression containing spark plugs towards the front and rear thereof, a plurality of circumferential fins in said depression, said fins being cutaway around each spark plug to provide an air entrance and exit, and air scoops communicating therewith.

5. A cylinder head having a depression, concentric fins in said depression, the inner fin being cylindrical and the others cut-away at front and rear segments to provide for bifurcated circumferential flow through said other fins around said central cylindrical fin, and an air scoop means adapted to induce such flow.

6. In a circular reentrant cylinder head, a plurality of concentric annular fins extending from the surface of the head to a point substantially flush with the top thereof, said fins having opposed segmental cutouts extending through a portion of their depth to provide air entrance and exit zones, and entrance and exit air scoops leading air to and from the fins in a direction substantially parallel to the axis thereof, said cutouts providing for the entrance and exit of air to and from the interfin spaces without sudden changes in the direction thereof.

7. In combination with a cylinder head having a depression, concentric annular fins within the depression, the outer fin edges being cut away to comprise opposed segmental air entrance and exit zones, and means for guiding cooling air to and from respective zones.

KENNETH A. BROWNE. 

